p461
Entasis

Article by Anthony Rich, Jun. B.A. of Caius College, Cambridge
on p461 of

ENTASIS
(ἔντασις). The most ancient columns now existing are remarkable for the extreme diminution of the shaft between its lower and upper extremity, the sides of which, like those of a cone, converge immediately and regularly from the base to the neck, so that the edge forms a straight line — a mode of construction which is wanting in grace and apparent solidity. To correct this, a swelling outline, called entasis (Vitruv.
III.2,
IV.3), was given to the shaft, which seems to have been the first step towards combining grace and grandeur in the Doric column.

The original form is represented by the figure on the left in the annexed woodcut, which is taken from the great temple at Posidonia (Paestum), which is one of the most ancient temples now remaining; that on the right shows the entasis, and is from a building of rather later construction in the same city. Two other examples of the same style are still to be seen in Italy, one belonging to an ancient temple at Alba Fucinensis (Piranesi, Magnif. de' Rom. tav. 31 fig. 6), and the other at Rome, on the sepulchre of C. Publicius (Ib. fig. 7).

In the example at Paestum the greatest deviation which the curved edge of the column makes from the straight line of the cone of which the pillar may be considered as a part, is at about the middle of the height, but it still keeps within the line of a perpendicular drawn from the circumference of the base; or, in other words, the column is thickest at the base: both of these properties are clearly shown by the dotted lines in the woodcut (comp. Stieglitz, Archäol. d. Baukunst, vol. I p161).

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